A popular type of communication interconnect, such as employed in computer systems, is the peripheral component interconnect (PCI). The PCI acts like a bridge, which isolates a host processor from the peripherals, allowing the host to run faster. A successor comprises the PCI Express (PCIe) which provides higher performance while maintaining compatibility with existing PCI arrangements. PCI Express protocol is more complex, with three layers—the transaction, data link and physical layers serving as a switch function. The PCIe switch needs to follow certain ordering rules set by specifications. As a result, the PCIe favors post transmissions over non-post transmissions in that all read or other non-post transmission requests or completions, with some exceptions, wait for the write or post transmission requests to be completed and flushed out.